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Article: Discussing Red 57:1, UV flexo ink and Yellow 14.(technicalTIDBITS)
- Article from:
- Ink World
- Article date:
- April 1, 2005
- Author:
CopyrightCOPYRIGHT 2005 Rodman Publishing. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Editor's Note: Lisa Hahn is a widely-respected expert in ink formulation and pigment dispersion technology, and will be answering your questions in her column.
Q: I've noticed that with magenta (red 57:1) pigment in a water-based dispersion, I can initially get a good liquid dispersion. However, over time, the product bodies up. Why is this happening and what can I do about it?
A: This is a common problem due to the chemical nature of the pigment. Red 57:1 and other metallized azo red pigments coordinate an organic molecule to a metal cation.
The electronic interaction between the metal cation and the organic portion of the pigment is partially ...